Well I ride at about 3000 elevation, so for my shee the 250 was a little rich. I am running 290's right now, with everything in my sig, my plugs are PERFECTLY Brown, but that is my shee. To me if you are running 280-300 mains with just your lid off, that sounds rediculously rich. But Hey, I'm no pro. Every banshee runs different and responds different to different mods. My advise to you Watkins is start with a little bigger main 250...and go from there...if it bogs down a little bit, your rich. Do a plug chop after wot and you will know where you are at.